Controlled periodic illumination in semiconductor photocatalysis

Abstract

Please cite this article as: Oluwatosin Tokode, Radhakrishna Prabhu, Linda Lawton, Peter K.J.Robertson, Controlled periodic illumination in semiconductor photocatalysis, Journal of Photochemistry and Photobiology A: Chemistry http://dx.doi.org/10.1016/j.jphotochem. 2015.12.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.  Experimental and theoretical studies are examined with emphasis on two theoretical models. A Langmuir-Hinshelwood model for incorporating CPI failed to predict photocatalytic rates. A quantum yield model showed good agreement with experimental data. Results from previous as well as some of the most recent studies indicate potential applications of controlled periodic illumination in areas other than just the improvement of the efficiency of the photocatalytic process.

An investigation of the role of pH in the rapid photocatalytic degradation of MCPA and its primary intermediate by low-power UV LED irradiation

“…With continued advancements in the field, there is now increased focus on developing systems that are both energy efficient and have a view towards larger scale deployment. The shift from traditional high-power arc lamps to low power or light emitting diode (LED) alternatives is evident in recent literature [18][19][20][21][22]. The advantages of a LED driven system go beyond the generic benefits of energy and cost efficiency and can include specific wavelength matching to catalyst bandgap to minimise 'wasted' photons, versatility and flexibility in geometrical LED arrays to improve light distribution and penetration, and narrow viewing angles to ensure direct irradiation of a specific catalytic area within a reactor.…”

Photocatalytic Degradation of Microcystins by TiO2 Using UV-LED Controlled Periodic Illumination

“…Although the PTT membrane provided a more practical option for water treatment, the reduced surface area relative to a slurry reactor imposed mass-transfer limitations. Because the rates of adsorption and desorption to the surface of the catalyst were significantly slower than the rate of electron-hole pair formation and recombination, the process of adsorption and desorption was rate-limiting [24,27]. This had a significant impact on the photonic efficiency of the system.…”

In situ Decolorization Monitoring of Textile Dyes for an Optimized UV-LED/TiO2 Reactor

“…Current photocatalytic processes in aqueous solutions involve different types of reactors [13][14][15][16][17][18][19][20][21][22], which can be classified in different groups according to their geometry (e.g., tubular or cylindrical, rectangular or square reactors, etc. ), liquid agitation techniques (e.g., continuous flow reactors, e.g., stirrer rotation) and lighting source including mainly low or medium pressure ultraviolet lamps [23][24][25][26][27], currently being replaced by LED lighting [28][29][30][31][32][33][34], which can reduce the size of the reactors, allowing the making of compact photo reactors known as mini reactors or micro reactors [35][36][37]. These reactors usually work with less than one liter of water [33][34][35][36][37][38][39][40][41][42], using photocatalysts either in suspension [41][42][43][44][45] or immobilized [46][47][48].…”